The government licensed the Reform Front party making it Tunisia's 118th legal party, the Al-Maghreb newspaper reported.
Mohammed Khoja, the head of the Reform Front, has said his party is committed to democracy.
Islamist parties were banned under Zine al-Abidine Ben Ali who was the Arab world's first state leader to be toppled during last year's Arab Spring protest movement.
The Salafi branch of Sunni Islam is closely associated with a puritanical interpretation of religion.
The moderate Islamist Ennahda party now heads the government after winning 42 percent of seats in Tunisia's first free parliamentary election in October.